Amount Of Orthodontic Tooth Movement Research Articles

Variation of gingival crevicular fluid volume in early orthodontic tooth movement with clear aligner: A pilot study

Objectives: The objective of this pilot study was to evaluate the crevicular fluid volume (GCF) increase from a quantitative point of view in the first 8 hours of clear aligner treatment. Then, its variation and the amount of Orthodontic Tooth Movement (OTM) obtained with clear aligners was evaluated considering two different protocols, one of 20 h and one of 12 h. Material and Methods: A total of 10 healthy, adult patients were selected to participate in a split-mouth study where an orthodontic treatment with clear aligners was planned. Vestibular crown uncontrolled tipping was planned for upper lateral-posterior sectors. At 0H (baseline), and every hour for the first 8 hours of use, three GCF samples were collected. Then, all patients were asked to wear one random half of the upper aligner for 12 hours per day (Group 1) and the other half for 20 hours per day (Group 2). The GCF samples were measured using the Periotron 8000 device to quantify inflammation. Then, the amount of movement obtained was calculated by considering the FA point shift in mm with Geomagic X Control Software. Results: No differences were found between the extent of inflammation in terms of GCF volume and hours of intermittent force application (group 1 vs group 2). Conclusion: The amount of GCF assessed through Periotron 8000 increases significantly from the moment forces are applied through clear aligners. Considering the limitations of the following pilot study, it would appear that the GCF amount is directly related to the amount of movement obtained.

The influence of fluoxetine on orthodontic tooth movement in rats.

This study aimed to evaluate the effects of chronic use of fluoxetine on the amount of orthodontic tooth movement and tissue changes in rats. A total of 192 Wistar rats were divided into 4 groups: S, 0.9% saline solution; F, 20 mg/kg of fluoxetine; SM, 0.9% saline solution with orthodontic movement; and FM, 20 mg/kg of fluoxetine with orthodontic movement. After 30 days of daily saline or fluoxetine administration, an orthodontic device (25cN) was used to mesially displace the first molar in animals of the groups SM and FM. The animals were euthanized 2, 7, 14, and 28 days after placement of the orthodontic appliances and animals of groups S and F were euthanized at the same time. The assessment of tooth movement was made in gypsum castings, the collagen neoformation was assessed by polarization microscopy, the number of osteoclasts and root resorption were evaluated using tartrate-resistant acid phosphatase, and presence of hyalinized areas was assessed by hematoxylin-eosin staining. Fluoxetine did not affect the amount of tooth displacement, percentage of collagen, number of osteoclasts, and presence of hyalinized areas (P>0.05). There was a higher frequency of root resorption areas in the FM group than in the SM group only on the second day (P<0.05). The findings of this study show that chronic use of 20 mg/kg fluoxetine does not affect the amount of tooth movement, collagen neoformation, number of osteoclasts, or hyalinized areas and does not affect root resorption until the last day of orthodontic movement.

Effects of Type and Amount of Orthodontic Tooth Movement on Digital Model Superimposition Accuracy

To assess the impact of type or amount of tooth movement on the success of 3D model superimposition by using two different algorithms. The sample consisted of pre-treatment digital maxillary models of forty patients. Eight different groups were created by applying 8 different virtual setups to each model. Teeth crowns were moved 1mm or 2mm in different directions (sagittal, transversal, vertical, combination) using the Ortho Analyzer software. Each model obtained from the virtual setup was overlapped with the original model using the landmark-based (LB) and local-best-fit (LBF) algorithms. In the post-superimposition assessment, the area of the palate vault which was not affected by teeth movements was selected. Both groups and algorithms were compared using RMS (root mean square) and PMA (percentage of perfectly matched areas) numeric data. In addition, the displacement of the right canine (RC) was measured after superimposition. The comparison of the superposition outcomes among the groups was evaluated with one-way ANOVA and Kruskal Wallis. The student t-test was used to compare two algorithms. Both algorithms were not affected by the type of tooth movement. However, the increase in the amount of tooth movement negatively affected the performance of the LB algorithm. LBF achieved the model superimpositions more effectively and faster than LB. No difference was found in RC measurements between the LB and LBF algorithms. The results indicate that LBF offers more sensitive and successful 3D superimposition models. The performance of the LB algorithm was, however, acceptable for analysis of 3D teeth movement.

Effect of ovariectomy-induced osteoporosis on the amount of orthodontic tooth movement: a systematic review of animal studies

Understanding the impact of osteopenia and osteoporosis on orthodontic tooth movement could be of benefit to the orthodontist, but research in humans presents practical and ethical problems. The ovariectomized animal model could provide useful information on osteoporosis. To compare the amount of tooth movement during or after the application of orthodontic forces between ovariectomized animals and control or sham-operated subjects. Unrestricted searches in seven databases and manual searching of the reference lists in relevant studies were performed up to February 2021 (PubMed, Central, Cochrane Database of Systematic Reviews, Scopus, Web of Science, Arab World Research Source, ProQuest Dissertations, and Theses Global). We searched for studies quantitatively comparing the amount of tooth movement during or after the application of orthodontic forces between ovariectomized animals and control or sham-operated subjects. Following study retrieval and selection, relevant data were extracted, and the risk of bias was assessed using the SYRCLE's Risk of Bias Tool. Exploratory synthesis and meta-regression were carried out using the random effects model. Thirteen studies were finally selected and no specific concerns regarding bias were identified. During the active period, ovariectomy was associated with a statistically significant acceleratory effect on the rate of orthodontic tooth movement compared to non-treated rats (3 weeks; 4 studies, 0.15 mm more movement in the ovariectomized rats; 95 per cent confidence interval: 0.10-0.19; P = 0.000). Exploratory meta-regression showed that this difference could increase over time. Following force discontinuation, no statistically significant differences were observed [3 weeks; 1 study (median ± SE), Ovariectomy group: 0.30 ± 0.04 mm; Sham operation group: 0.18 ± 0.03; P = 0.1558]. Ovariectomy-induced osteoporosis may affect the rate of orthodontic tooth movement. Although animal studies should be approached with caution regarding their translational potential, the safe practice would suggest that one should consider potential implications. PROSPERO (CRD42018118003).

Which method is more effective for accelerating canine distalization short term, low-level laser therapy or piezocision? Asplit-mouth study.

This study evaluated and compared the effects of low-level laser therapy (LLLT) and piezocision on the amount of orthodontic tooth movement. Forty maxillary canines from 20patients (mean age, 16.35 ± 1.14years) were evaluated in asplit-mouth design study. Miniscrew-supported canine distalization was performed. Piezocision was applied in the right maxillary canine region, and the left maxillary canines were irradiated with adiode laser (940 nm, 5 J/cm2). LLLT was performed on day0 and days 3, 7, 14, 21, and 28 after the start of canine distalization in the first 4‑week period. Data were evaluated at baseline (T0) and after 4 (T1), 8 (T2), and 12 (T3) weeks. The amount of canine movement was determined from three-dimensional models, and the angulation of canines and first molars was analyzed based on lateral cephalograms. Intragroup and intergroup comparisons of canine distalization were performed for four different time intervals (T0-T1, T1-T2, T2-T3, T0-T3). The canine tooth movement in the T0-T1 period was significantly greater in the LLLT group compared to the piezocision group. No statistically significant differences were observed between the groups for the T1-T2, T2-T3, and T0-T3 periods. The amount of canine distalization in the T0-T1 period was significantly greater than that in the T1-T2 and T2-T3 periods in both groups. Tooth movement during the T1-T2 period was higher than that in the T2-T3 period in the LLLT group. Cephalometric evaluation revealed no statistically significant difference between the groups with respect to canine and first molar angulation. Although laser application seems more effective during the first 4‑week period, considering the 12-week period, the effects of LLLT and piezocision on orthodontic tooth movement during canine distalization were similar.

Does the rate of orthodontic tooth movement change during pregnancy and lactation? A systematic review of the evidence from animal studies

BackgroundThe changes in bone homeostasis observed during pregnancy and lactation could result in alterations in the rate of orthodontic tooth movement, but research in human subjects presents significant ethical and practical limitations. Our aim was to compare the amount of orthodontic tooth movement between pregnant/lactating or not animals.MethodsWe searched without restrictions 8 databases and performed hand searching until July 2019 (PubMed, Central, Cochrane Database of Systematic Reviews, SCOPUS, Web of Science, Arab World Research Source, ClinicalTrials.gov, ProQuest Dissertations and Theses Global). We searched for studies comparing quantitatively the amount of orthodontic tooth movement between pregnant/lactating or not animals. Following retrieval and selection of studies, the collection of related data was performed and the risk of bias was assessed using the SYRCLE’s Risk of Bias Tool. Exploratory synthesis was carried out using the random effects model.ResultsFour studies were finally identified raising no specific concerns regarding bias. One study showed that lactation increased the rate of tooth movement by 50 % [p < 0.05]. Although an overall increase was noted in the pregnancy group as well, it did not reach statistical significance [3 studies, Weighted Mean Difference: 0.10; 95% Confidence Interval: − 0.04 - 0.24; p = 0.165].ConclusionsThe metabolic changes occurring during pregnancy and lactation may have an impact on the rate of tooth movement in animals. Although these animal experimental results should be approached cautiously, it could be safe practice to consider the impact of these physiological changes in the clinical setting.RegistrationPROSPERO (CRD42018118003).

To determine the effect of material fatigue of aligners in oral environment and to describe and quantify the type and amount of Orthodontic tooth movement produced by clear aligners

Introduction: The following observations regarding tooth movement with Invisalign aligners resulted from a randomized and controlled clinical trial1. In a two-week prescription cycle of wearing an aligner, more orthodontic tooth movement (OTM) was seen in the first week as compared to the second week.1.In a two-week prescription cycle of wearing an aligner, more orthodontic tooth movement (OTM) was seen in the first week as compared to the second week.2.The exact expected result from the comparison was not obtained.3. Different individuals depicted different OTM.The results in this study have certain clinical implications which require further research and a more thorough study.Aim: The primary aim of this study was to determine whether these observations were due to material fatigue of the aligners in the oral environment. The secondary aim of this study was to describe and quantify the type and amount of OTM produced by clear aligners.Material and Method: A single centre prospective clinical trial was completed, comparing 15 subjects treated over a course of eight weeks with a control group of 37 subjects study with similar population demographics and nearly identical study design. An upper central incisor was programmed to move two mm over eight weeks, or 0.5 mm every two weeks, using Invisalign® aligners. The treatment subjects changed to a fresh aligner with the same prescription after one week, and the control subjects wore each aligner for the prescribed two weeks. Every week impressions were taken with polyvinyl siloxane (PVS) and models were fabricated digitally to measure OTM. In addition, initial and final cone beam computed tomography (CBCT) images were obtained from the treatment subjects only, to describe and measure OTM.Result: No significant difference was seen found in OTM in individuals who were wearing the initial aligner for a period of two weeks vs. those individuals who switched to a fresh aligner after a period of one week. The OTM variability in the second week was seen due to the material wear and fatigue present. There was, however, a significant difference in OTM during the first week vs. the second week of any given two-week cycle, for both groups. When OTM was measured from the centre of the clinical crown, the two mm prescription of the aligners was not fully expressed in any of the 15 treated subjects.Conclusion: High variability was observed. In addition, CBCT data indicated that: 1) the target teeth experienced tipping that was uncontrolled in nature, with the median rotation center at 41% of the length of the root apical to the alveolar crest, 2) although only one central incisor was planned to move, the contralateral central incisor felt a reactive force and got rotated in the direction opposite that of the target tooth, 3) seven of the 15 subjects experienced a net anteroposterior (A-P) change of less than 1.9 mm between the midpoint of the incisal edge of the target tooth and the contralateral central incisor, and 4) the results of an exploratory data analysis attempting to correlate biologic variables with OTM revealed some trends, but additional research is required before making conclusions.

TNF-α is responsible for the contribution of stromal cells to osteoclast and odontoclast formation during orthodontic tooth movement.

Compressive force during orthodontic tooth movement induces osteoclast formation in vivo. TNF-α plays an important role in mouse osteoclast formation and bone resorption induced by compressive force during orthodontic tooth movement. Stromal cells, macrophages and T cells take part in TNF-α-induced osteoclast formation in vitro. Root resorption caused by odontoclasts is a major clinical problem during orthodontic tooth movement. In this study, we determined the cell type targeted by TNF-α during compressive-force-induced osteoclast and odontoclast formation to elucidate the mechanism of bone and root resorption in vivo. An orthodontic tooth movement mouse model was prepared with a nickel-titanium closed coil spring inserted between the maxillary incisors and the first molar. Using TNF receptor 1- and 2-deficient (KO) mice, we found that osteoclast and odontoclast formation was mediated by TNF-α in orthodontic tooth movement. We generated four types of chimeric mice: wild-type (WT) bone marrow cells transplanted into lethally irradiated WT mice (WT>WT), KO bone marrow cells transplanted into lethally irradiated WT mice (KO>WT), WT bone marrow cells transplanted into lethally irradiated KO mice (WT>KO), and KO marrow cells transplanted into lethally irradiated KO mice (KO>KO). Using anti-CD4 and anti-CD8 antibodies, T cells were eliminated from these mice. We subjected these chimeric mice to orthodontic tooth movement. Orthodontic tooth movement was evaluated and tartrate-resistant acid phosphatase-positive cells along the alveolar bone (osteoclasts) and along the tooth root (odontoclasts) were counted after 12 days of tooth movement. The amount of orthodontic tooth movement, and the number of osteoclasts and odontoclasts on the compression side were significantly lower in WT>KO and KO>KO mice than in WT>WT and KO>WT mice. According to these results, we concluded that TNF-α-responsive stromal cells are important for osteoclast and odontoclast formation during orthodontic tooth movement.

Infrared Light-Emitting Diode (LED) Effects on Orthodontic Tooth Movement.

The present study aimed to analyze the effect of LED phototherapy on the presence of hyalinization and root resorption during orthodontic tooth movement (OTM) in rats and to measure the amount of tooth movement. Eighty rats were allocated into two groups: LED and control (CON), where the LED rats were irradiated with infrared LED (850 nm, 30 mW) for 5 min during the first five days of OTM and where controls were not irradiated. Both groups were subdivided into four subgroups (n=10) according to the date of euthanasia (4, 7, 14 and 21 days). Five out of ten LED21 and five of ten CON21 rats were submitted to micro-computed tomography (μCT); μCT scans were taken on days 0, 7, 14 and 21. For histological study, maxillae were processed to light microscopy using Hematoxylin-Eosin (HE) and Tartrate-Resistant Acid Phosphatase (TRAP) histochemistry. The amount of tooth movement did not differ between LED and CON. Hyalinization was observed at the pressure areas in both groups, and it did not show a statistically significant difference between the groups. Root resorption was also observed in both groups after 7 days and it did not represent any differences between the two groups. LED phototherapy was not able to increase the amount of OTM. Similar characteristics of hyalinization and root resorption were observed in both groups.

The Effect of a Plasma With Platelet-rich Fibrin in Bone Regeneration and on Rate of Orthodontic Tooth Movement in Adolescents

The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF), placed in extraction sockets, on bone regeneration and orthodontic tooth movement in adolescents. Fourty extraction sockets from twenty patients requiring extraction of first premolars based on their orthodontic treatment plan participated in this split-mouth clinical trial. Immediately, the teeth adjacent to the defects were pulled together by a NiTi closed-coil spring with constant force. The bone regeneration and the amount of orthodontic tooth movement was evaluated.

Macroscopic and microscopic evaluation of flapless alveolar perforations on experimental tooth movement.

Objective: The aim of this study was to evaluate a flapless surgical technique as an alternative to traditional alveolar corticotomy used to accelerate orthodontic tooth movement (OTM). Methods: To induce OTM in Wistar rats, 40 cN of orthodontic force were applied to the maxillary left first molars. Forty rats were distributed into control groups (CG1, CG3, CG7 and CG14) and experimental groups (n= 5), in which alveolar perforations were made using a spear-shaped guide bur (EG1, EG3, EG7, EG14). Euthanasia dates were set at 1, 3, 7 and 14 days, respectively, after tooth movement began. The amount of OTM was measured with a caliper, and osteoclasts present in the periodontal ligament of the mesial root of the moved tooth were counted by means of histological evaluation (tartrate-resistant acid phosphatase staining, TRAP). Results: Although there was no difference in the amount of OTM within subgroups of corresponding experimental periods (p> 0.05), when EG14 and CG14 were compared, a larger number of osteoclasts was counted in the experimental group (p< 0.00). Conclusion: The authors concluded that flapless cortical alveolar perforations led to more intense osteoclastic activity on the fourteenth day; nevertheless, no evidence of accelerated OTM could be noted.

The effects of alveolar decortications on orthodontic tooth movement and bone remodelling in rats.

Alveolar decortication (AD) is a minimally invasive procedure that can be performed in the orthodontic office as an intervention to accelerate tooth movement. There is a gap in the literature evaluating the earlier and delayed responses after AD using lighter orthodontic forces in a rat model. Therefore, the aim of this study was to determine the effects of AD in the amount of orthodontic tooth movement and on alveolar bone remodelling in a rodent model, after 7 or 14 days. A total of 32 15-week-old male Wistar rats were used in four treatment groups: (1) orthodontic spring only (7 days), (2) orthodontic spring only + AD (7 days), (3) orthodontic spring only (14 days), and (4) orthodontic spring only + AD (14 days). A closed coil nickel-titanium spring delivering 8-10 g of force was used to move the molar mesially. Alveolar decortication was done using a high speed, quarter round bur adjacent to the left first maxillary molar, on the palatal alveolar bone. At each endpoint, rats were sacrificed and microfocus computed tomography and histological analysis were performed. The spring + AD group presented with a significant increase in the rate of tooth movement when compared with spring only group, 7 and 14 days after the beginning of the experiments. In addition, the spring + AD group had a significant decrease in bone volume and tissue density and a significant increase in the trabecular spacing and the number of osteoclasts at 7 and 14 days. Furthermore, a fibrous tissue was found to replace the alveolar bone in the spring + AD group at day 14. Alveolar decortications enhanced bone remodelling around the tooth movement region and could be used as an adjunct surgical procedure to accelerate the rate of tooth movement.

Comparison of the effects of three surgical techniques on the rate of orthodontic tooth movement in a rat model.

To evaluate the effect of corticotomy and corticision, with and without a full mucoperiosteal flap, on the rate of tooth movement and alveolar response in a rat model. Sixty male, 6-week-old Wistar rats were divided into five groups based on surgical procedure, as follows: control (no tooth movement), orthodontic tooth movement (OTM) only, corticotomy, corticision, and corticision with full mucoperiosteal flap (corticision + flap). A force of 10-15g was applied from the maxillary left first molar to the maxillary incisors using nickel-titanium springs. Surgery was performed at the time of appliance placement (day 0), and tooth movement occurred for 21 days. Micro-computed tomography was performed on day 21 to evaluate the amount of tooth movement and alveolar bone parameters. Histomorphometry, including tartrate-resistant acid phosphatase staining, was performed to quantify the osteoclast parameters at day 21. No statistical differences in the amount of OTM, bone volume fraction, and tissue density and the osteoclast parameters were found among all experimental groups. Corticotomy and corticision, with or without a full mucoperiosteal flap, did not show a significant effect on either the OTM magnitude or alveolar bone response.

Contribution of atypical chemokine receptor 2/ackr2 in bone remodeling

IntroductionBone remodeling is a tightly regulated process influenced by chemokines. ACKR2 is a decoy receptor for CC chemokines functioning as regulator of inflammatory response. In this study we investigated whether the absence of ACKR2 would affect bone phenotype and remodeling induced by mechanical loading. MethodsAn orthodontic appliance was placed between incisors and first molar of ACKR2 deficient (ACKR2−/−) and C57BL6/J (wild-type/WT) mice. Microtomography, histology and qPCR were performed to evaluate bone parameters, orthodontic tooth movement (OTM), bone cells counts and the expression of ACKR2, bone remodeling markers, CC chemokines and chemokines receptors. Bone marrow cells (BMC) from WT and ACKR2−/− mice were differentiated in osteoclasts and osteoblasts for analysis of activity and expression of specific markers. ResultsMechanical stimulus induced ACKR2 production in periodontium. The expression of ACKR2 in vitro was mostly detected in mature osteoclasts and early-differentiated osteoblasts. Although ACKR2−/− mice exhibited regular phenotype in maxillary bone, the amount of OTM, osteoclasts counts and the expression of pro-resorptive markers were increased in this group. In contrast, the number of osteoblasts and related markers were decreased. OTM resulted in augmented expression of CC chemokines and receptors CCR5 and CCR1 in periodontium, which was higher in ACKR2−/− than WT mice. In vitro experiments demonstrated an augmented formation of osteoclasts and diminished differentiation of osteoblasts in ACKR2−/− mice. ConclusionsThese data suggests that ACKR2 functions as a regulator of mechanically-induced bone remodeling by affecting the differentiation and activity of bone cells and the availability of CC chemokines at periodontal microenvironment. Therapeutic strategies based on increase of ACKR2 might be useful to hinder bone loss in inflammatory conditions.

Effect of Methylphenidate on Orthodontic Tooth Movement and Histological Features of Bone Tissue in Rats: An Experimental Study.

Methylphenidate is a psychostimulant drug, which is commonly used by children and teenagers. This age group receives most orthodontic treatment. Effect of this drug on tooth movement is unknown. The aim of this study was to evaluate the effect of methylphenidate on orthodontic tooth movement and histological features of bone tissue in rats. Forty-two Wistar rats (male) were selected and divided to three groups, randomly (n=14). The control group (Group 1) received no drug, the experimental Group 2 received a constant dose of methylphenidate daily for 14 days while the experimental Group 3 received increasing doses of methylphenidate daily. To exert force, a NiTi coil spring was placed between the maxillary right first molar and the maxillary right central incisor. At the end of the study period, the amount of tooth movement was measured and then the rats were sacrificed for histological analysis of bone tissue. Differences between the experimental groups were analysed using Kruskal-wallis and Mann-Whitney U tests. No significant differences were found in the amount of orthodontic tooth movement or osteoclasts and lacunae, between the experimental groups (p>0.05). Mann-Whitney U analysis showed significant differences in the depth of resorption lacuna between Group 2 and 3 (p=0.037). Methylphenidate has no significant effect on orthodontic tooth movement or histological features of bone tissue in rats.

Age-related effects on osteoclastic activities after orthodontic tooth movement.

ObjectivesTo elucidate the effects of age on the expression levels of the receptor activator of the nuclear factor-κB ligand (RANKL) and osteoclasts in the periodontal ligament during orthodontic mechanical loading and post-orthodontic retention.Materials and MethodsThe study included 20 male Sprague-Dawley rats, ten in the young group (aged four to five weeks) and ten in the adult group (aged 18 to 20 weeks). In each rat, the upper-left first molar was subjected to a seven-day orthodontic force loading followed by a seven-day retention period. The upper-right first molar served as a control. The amount of orthodontic tooth movement was measured after seven-day force application and seven-day post-orthodontic retention. The expression levels of RANKL and the tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts were evaluated on day 7 (end of mechanical force loading) and day 14 (after seven days of post-orthodontic retention). Statistical analysis was performed using the t-test, and significance was set at p < 0.05.ResultsThere was no significant difference between the amount of tooth movement in the young group (0.96, standard deviation (sd) 0.30mm) and that in the adult group (0.80mm, sd 0.28) (p > 0.05) after the seven-day force application. On the compression side, the expression of RANKL and TRAP-positive osteoclasts in both the young and the adult groups increased after the application of force for seven days, and then decreased at the end of the seven-day retention period. However, by the end of the period, the expression of RANKL on the compression side dropped to the control level in the young group (p > 0.05), while it was still higher than that on the control side in the adult group (p < 0.05). The expression of RANKL on the compression side did not show significant difference between the young and the adult groups after seven-day force application (p > 0.05), but it was significantly higher in the adult group than that in the young group after seven-day post-orthodontic retention (p < 0.05). Similarly, the decreasing trend of TRAP-positive osteoclasts during the retention period in the adult group was less obvious than that in the young group.ConclusionsThe bone-resorptive activity in the young rats was more dynamic than that in the adult rats. The expression of RANKL and the number of osteoclasts in adult rats did not drop to the control level during the post-orthodontic retention period while RANKL expression and the number of osteoclasts in young rats had returned to the baseline.Cite this article: X. Li, M. Li, J. Lu, Y. Hu, L. Cui, D. Zhang, Y. Yang. Age-related effects on osteoclastic activities after orthodontic tooth movement. Bone Joint Res 2016;5:492–499. DOI: 10.1302/2046-3758.510.BJR-2016-0004.R2.

Local infiltration of Vitamin D3does not accelerate orthodontic tooth movement in humans:A preliminary study

Objective: To determine the effect of Vitamin D3 on the rate and amount of orthodontic tooth movement in humans when injected locally at the site. Materials and Methods: A prospective, split-mouth clinical trial was carried out on 15 subjects who were referred for bilateral therapeutic extraction of the first premolars followed by canine retraction in the maxillary arch. Vitamin D3 in a vehicle of local anesthetic solution was injected into the buccal vestibule immediately distal to the canine to be retracted on the experimental side; on the contralateral side, only local anesthetic solution as control was injected into the correspnding site on the 7th, 21st, and 47th days of canine retraction. The amount of canine retraction was assessed using the palatal rugae as stable landmarks, and the values obtained were compared using preand postcanine retraction occlusograms. Results: The experimental teeth whose gingivae had received injections containing Vitamin D3 had moved considerably less than had the matched control teeth (P , .001). Conclusions: Localized injection of vitamin D3 produces a significantly decreased rate and amount of tooth movement in humans. (Angle Orthod. 0000;00:000–000.)

Impact of extracorporeal shock wave therapy (ESWT) on orthodontic tooth movement—a randomized clinical trial

This randomized clinical trial investigated the effect of extracorporeal shock waves on the amount of orthodontic tooth movement and periodontal parameters. Twenty-six adult orthodontic patients participated in this clinical trial; all of them receiving lower second molar mesially directed movement. The fixed orthodontic device included superelastic coil springs (200cN) and miniscrews as temporary anchorage device. The active treatment group received a single shock wave treatment with 1,000 impulses in the region of tooth movement. The placebo group was treated with deactivated shock wave applicator with an acoustic sham. The study period lasted 4months with amonthly data exploration. No statistically significant difference in posterior-anterior tooth movement between the treatment and placebo group was seen during observation period. Gender had no significant influence on tooth movement in either group. No significant difference occurred in mesio-distal tipping and rotation, but a significant difference (p = 0.035) in bucco-lingual tipping of the molars was found. Periodontal status of the patients (sulcus probing depth, gingival index) did not significantly differ in both groups. The plaque index showed a significant difference (p = 0.003). Single application of extracorporeal shock wave treatment was associated neither with a statistically significant acceleration of tooth movement nor with an altered periodontal status in vivo. Shock waves showed no harmful effects in the investigated area. Their clinical use for lithotripsy during orthodontic therapy might be permitted.

Examination of extremely low frequency electromagnetic fields on orthodontic tooth movement in rats

The purpose of this study was to evaluate whether 50 Hz extremely low frequency electromagnetic fields (ELF-EMFs) affect the amount of orthodontic tooth movement in rats. The experiments were performed on 18 male Sprague-Dawley rats. The rats were randomly divided into three groups (n = 6): cage-control (Cg-Cnt) group (n = 6); sinusoidal electromagnetic field (SEMF) group (n = 6); and pulsed electromagnetic field (PEMF) group (n = 6). In SEMF and PEMF groups, rats were subjected to 1.5 mT EMF exposure eight hours per day for eight days. In order to obtain tooth movement, holes were drilled on the right and left maxillary central incisors of the rats at a distance 1.5–2 mm away from the gingiva and 20 g of orthodontic forces were applied to the teeth. Generated linear model for repeated measures and Bonferroni tests were used to evaluate the differences between the groups. Interactions among groups by days were found by using Pillai's trace multivariate test. The results showed that significant differences were present among the groups (F = 5.035; p = 0.03) according to the extent of tooth movement. Significant differences between the amount of tooth movements were determined especially after the fifth day and the following days six, seven and eight (p < 0.001). Within the limitations, according to the results of the present study, the application of ELF-EMF accelerated the orthodontic tooth movement in rats.

Bis-enoxacin Inhibits Bone Resorption and Orthodontic Tooth Movement

Enoxacin inhibits binding between the B-subunit of vacuolar H+-ATPase (V-ATPase) and microfilaments, and also between osteoclast formation and bone resorption in vitro. We hypothesized that a bisphosphonate derivative of enoxacin, bis-enoxacin (BE), which was previously studied as a bone-directed antibiotic, might have similar activities. BE shared a number of characteristics with enoxacin: It blocked binding between the recombinant B-subunit and microfilaments and inhibited osteoclastogenesis in cell culture with IC50s of about 10 µM in each case. BE did not alter the relative expression levels of various osteoclast-specific proteins. Even though tartrate-resistant acid phosphatase 5b was expressed, proteolytic activation of the latent pro-enzyme was inhibited. However, unlike enoxacin, BE stimulated caspase-3 activity. BE bound to bone slices and inhibited bone resorption by osteoclasts on BE-coated bone slices in cell culture. BE reduced the amount of orthodontic tooth movement achieved in rats after 28 days. Analysis of these data suggests that BE is a novel anti-resorptive molecule that is active both in vitro and in vivo and may have clinical uses. Abbreviations: BE, bis-enoxacin; V-ATPase, vacuolar H+-ATPase; TRAP, tartrate-resistant acid phosphatase; αMEM D10, minimal essential media, alpha modification with 10% fetal bovine serum; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; RANKL, receptor activator of nuclear factor kappa B-ligand; NFATc1, nuclear factor of activated T-cells; ADAM, a disintegrin and metalloprotease domain; OTM, orthodontic tooth movement.